The rule of Identity. X*1=X.
Divide both sides by x, and you get
X/X = 1
Let C be the amount of compost
T be the amount of topsoil
Each compost cost = $25
Cost of C compost = 25C
Each topsoil cost = $15
Cost of T topsoil = 15T
Amount of compost + amount of topsoil = 10
C + T = 10 -------> Equation 1
cost of C compost + cost of T topsoil = 180
25C + 15T = 180 --------> equation 2
Solve the first equation for C
C + T = 10
C = 10 - T
Now plug it in second equation
25C + 15T = 180
25 ( 10 - T) +15T = 180
250 - 25T + 15T = 180 (combine like terms)
250 - 10 T = 180 (Subtract 250 on both sides)
-10T = 180 - 250
-10T = -70 ( divide by -10 on both sides)
T = 7
She purchased 7 cubic yards of topsoil .
(a) 4
(b) y = sqrt(9 - (9/16)x^2)
The best guess to the formula using knowledge of the general formula for an ellipse is:
x^2/16 + y^2/9 = 1
(a). An ellipse is reflectively symmetrical across both the major and minor axis. So if you can get the area of the ellipse in a quadrant, then multiplying that area by 4 would give the total area of the ellipse. So the factor of 4 is correct.
(b). The general equation for an ellipse is not suitable for a general function since it returns 2 y values for every x value. But if we restrict ourselves to just the positive value of a square root, that problem is easy to solve. So let's do so:
x^2/16 + y^2/9 = 1
x^2/16 + y^2/9 - 1 = 0
x^2/16 - 1 = - y^2/9
-(9/16)x^2 + 9 = y^2
9 - (9/16)x^2 = y^2
sqrt(9 - (9/16)x^2) = y
y = sqrt(9 - (9/16)x^2)
Answer:
Step-by-step explanation:
Answer:
C+B
Step-by-step explanation:
you add A + B = C
